I think you have to take a moment and think about the number of assumptions and handwaving you just argued for:Well, that's the challenge the natural origin theory is going to have to explain and better full in information gaps.
A lucky recombination between strains spacially and species distanced from each other, and 1000 miles away from the sole outbreak in Wuhan. Another odd but lucky furin site insertion outta the blue, lack of known sequences establishing a pedigree, lack of known animal reservoirs, a lack of previously circulating virus, and a lab who holds a lot of the data locking down and not sharing what they working on nor large sections of their databases or unpublished virus samples.
Hanging hats that the wt Wuhan isn't fully optimized by a base pair (and hand waiving away the rest) in what's very visibly a multimodal environment won't be sufficiently convincing.
Beyond the science, the politics will certainly demand a much stronger explanation
1) Recombination is lucky: As previously mentioned, SARS-CoV-1 has evidence of 7 recombination sites and recombination has been well described for coronaviruses and can occur even in the controlled laboratory setting going back to 1985. What is so lucky about it?
2) Viruses are geographically static. What study demonstrates these coronavirus strains are so geographically static that 1000 miles is meaningful? Do you really want to invoke that viruses are so landlocked like that, especially when one of those viral strains was isolated from a flying mammal???
3) The furin site is unusual. As mentioned, furin sites are commonly gained and lost throughout the coronavirus family. Can anybody explain, if furin sites are so important for so many beta coronaviruses, why from the phylogenetic tree you linked to that Bat-CoV-HKU4 and Bat-CoV-HKU31 both lack them?
4) Lack of known sequences. This is the same argument that Creationists invoke: "Oh there's no common ancestor in the fossil record between humans and chimps... hence evolution is false!" Does one really want to rely on the argument that no closely related viruses will be found?
5) Lack of known animal reservoirs: What systematic study exists that has shown this where they looked for closest neighbors to SARS-CoV-2? Do you really want to bet the farm on that animal reservoirs will never be found?
6) A lack of a previously circulating virus... This would argue that SARS-CoV-1 or MERS should have never occurred because it wasn't circulating. Do you really want to assume that the ancestor of SARS-CoV-2 hasn't been circulating in its primary host? Again, do you really wish to make that argument?
Think about the amount of handwaving that is required to buy into your points. And the biggest handwave? Why somebody would decide to choose to study a bat coronavirus that has never been studied in the lab, never been isolated and grown in cell culture, and to want to study the pathogenicity of it? On top of it, why would somebody want to engineer the sequence of another coronavirus, that also has been never studied and never grown in cell culture into that virus? And then these researchers would have to work years to not only reverse engineer the virus, find the ideal culture conditions, determine optimal ways to detect the virus, only to study what? How can someone do "gain of function" research on something that nobody has established the baseline function? Why would one study not just one esoteric virus but two and invest years worth of necessary time to simply establish the tools to study these viruses? Why would a researcher not study other coronaviruses that have decades worth of studies and tools already available, and there are already two existing highly pathogenetic strains (SARS-CoV-1 and MERS)?